This proposal concerns the study of Men's Assessment of Social Support and Risk Networks. Unfortunately, relatively little is known about the particular social consequences of the aging of the HIV/AIDS population, either for the challenges faced by persons who live with HIV/AIDS (PWHIV) in later life or for the spread of HIV/AIDS. According to network-epidemiological studies, important clues may be found in the social networks of middle-aged and older men who have sex with men (MSM). The main goal of our research is to develop techniques for eliciting valid social network information from MSM who participate in the Multicenter AIDS Cohort Study (MACS). We propose to adapt egocentric social network elicitation techniques that are commonly used in social network studies to gather high-quality network information about both the supportive and risk- behavior networks of MSM. A pilot study will involve querying 60 seropositive and seronegative men participating in the Chicago site of the MACS about the structure of their support networks, drug-sharing networks, and sexual networks. Information will be collected during 20-30 minute face-to-face interviews. Respondents will provide information about the number of people in each of these networks, the nature of their contact with them, how they met, how much they know about those network members'contacts with each other, and what they know about those network members'HIV serostatus, risky behavior (e.g., intravenous drug sharing) behaviors and other risk factors. This information will also give us an idea of the extent of overlap between MSM's drug-sharing and sexual networks. When paired with other information collected in the MACS, this information will make it possible to examine the consequences of social networks both for the impact of HIV/AIDS on quality of life (QOL) as well as for the potential spread of HIV/AIDS in the "post-HAART era." Furthermore, these data will allow us to examine how knowledgeable MSM are about the risk-related aspects of their networks, such as to what extent the people with whom they share drugs also share drugs with each other. This reflects our belief that not being knowledgeable about one's supportive and/or risk networks is a risk factor in and of itself. These data will be validated against existing information in the MACS. This pilot study will be used to evaluate the feasibility of creating a Men's Network Structure Assessment (MNSA) module for inclusion in the MACS. This will make high-quality social- and risk-network data readily available to a large number of researchers who use the MACS, thus facilitating the use of social network analysis (SNA) in large, prospective study of MSM. Such data will help shed light on sociodemographic disparities in terms of quality of life (QOL) as well as group differences in risk-taking among PWHIV and provide a basis for targeted social network level interventions. 1 Men's Assessment of Social Support and Risk Network will provide new data regarding the consequences of the aging of the HIV/AIDS population by learning more about the social networks of middle-aged and older men who have sex with men (MSM). The project will develop techniques for eliciting valid social network information from MSM, providing the number of people in each of these networks, the nature of their contact with them, how they met, how much they know about those network members'contacts with each other, and what they know about those network members'HIV status, risky behavior behaviors and other risk factors. The study will also give us an idea of the extent of overlap between MSM's drug-sharing and sexual networks and the consequences of social networks both for the impact of HIV/AIDS on quality of life as well as for the potential spread of HIV/AIDS.